Salt marsh restoration surprise: A subordinate species accumulates and shares nitrogen while outcompeting salt marsh dominants
Selectively planting native species could guide ecosystem development toward wetland restoration targets, once we understand how influential species function, alone and in combination. Knowing that Triglochin concinna (arrow grass, Juncaceae) accumulates N in its perennial roots, we asked how it wou...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2022-12-01
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| Series: | Frontiers in Ecology and Evolution |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/fevo.2022.851055/full |
| _version_ | 1797975411744833536 |
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| author | Hem Nalini Morzaria-Luna Hem Nalini Morzaria-Luna Joy B. Zedler |
| author_facet | Hem Nalini Morzaria-Luna Hem Nalini Morzaria-Luna Joy B. Zedler |
| author_sort | Hem Nalini Morzaria-Luna |
| collection | DOAJ |
| description | Selectively planting native species could guide ecosystem development toward wetland restoration targets, once we understand how influential species function, alone and in combination. Knowing that Triglochin concinna (arrow grass, Juncaceae) accumulates N in its perennial roots, we asked how it would influence N dynamics on an excavated salt marsh plain at Tijuana Estuary, in southern California. We hypothesized that it would (a) accumulate N in roots and shoots, (b) reduce biomass of other marsh plain plants or, alternatively, (c) share N with neighbors as its litter decomposed and released N. We used 15N stable isotope enrichment to quantify N transfer between Triglochin and the marsh plain’s seven-species halophyte assemblage in field and greenhouse experiments. We also examined the effect of Triglochin on individual marsh plain species’ biomass and N accumulation. Triglochin had low shoot biomass (0.96 ± 0.5 g m−2 in field plots and 17.64 ± 2.2 g m−2 in greenhouse pots), high root:shoot ratios (4.3 in the field and 2.0 in the greenhouse), and high tissue N content (1.9 ± 0.2% in the field and 1.7 ± 0.1% in the greenhouse). Two productive perennials, Sarcocornia pacifica (pickleweed) and Frankenia salina (alkali heath), outgrew Triglochin; yet these biomass dominants produced 44%–45% less shoot biomass in greenhouse pots with Triglochin than without. However, we did not find this reduction in the field where roots were unconfined. In the greenhouse, δ15N values were higher for species grown with 15N-enriched Triglochin, indicating that this species made N available to its neighbors. The δ15N values for plants grown in the field exceeded background levels, also indicating that the marsh plain assemblage took up N released by Triglochin. We conclude that Triglochin can influence the restoration of salt marsh vegetation by accumulating N and releasing its tissue N to neighbors as leaves and roots decompose, while simultaneously reducing the biomass of neighbors. The seasonally deciduous Triglochin is low in shoot biomass, yet competitively superior in N uptake. Because this often-ignored species has limited tidal dispersal, we suggest restoration plantings, including tests of its ability to facilitate diversity where S. pacifica, the marsh plain dominant, might otherwise form monocultures. |
| first_indexed | 2024-04-11T04:35:06Z |
| format | Article |
| id | doaj.art-b77418c21b0b4f718318784c066f7f09 |
| institution | Directory Open Access Journal |
| issn | 2296-701X |
| language | English |
| last_indexed | 2024-04-11T04:35:06Z |
| publishDate | 2022-12-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Ecology and Evolution |
| spelling | doaj.art-b77418c21b0b4f718318784c066f7f092022-12-28T17:53:42ZengFrontiers Media S.A.Frontiers in Ecology and Evolution2296-701X2022-12-011010.3389/fevo.2022.851055851055Salt marsh restoration surprise: A subordinate species accumulates and shares nitrogen while outcompeting salt marsh dominantsHem Nalini Morzaria-Luna0Hem Nalini Morzaria-Luna1Joy B. Zedler2Department of Botany, University of Wisconsin-Madison, Madison, WI, United StatesVisiting Researcher, Northwest Fisheries Science Center, NOAA, Seattle, WA, United StatesDepartment of Botany and Arboretum, University of Wisconsin-Madison, Madison, WI, United StatesSelectively planting native species could guide ecosystem development toward wetland restoration targets, once we understand how influential species function, alone and in combination. Knowing that Triglochin concinna (arrow grass, Juncaceae) accumulates N in its perennial roots, we asked how it would influence N dynamics on an excavated salt marsh plain at Tijuana Estuary, in southern California. We hypothesized that it would (a) accumulate N in roots and shoots, (b) reduce biomass of other marsh plain plants or, alternatively, (c) share N with neighbors as its litter decomposed and released N. We used 15N stable isotope enrichment to quantify N transfer between Triglochin and the marsh plain’s seven-species halophyte assemblage in field and greenhouse experiments. We also examined the effect of Triglochin on individual marsh plain species’ biomass and N accumulation. Triglochin had low shoot biomass (0.96 ± 0.5 g m−2 in field plots and 17.64 ± 2.2 g m−2 in greenhouse pots), high root:shoot ratios (4.3 in the field and 2.0 in the greenhouse), and high tissue N content (1.9 ± 0.2% in the field and 1.7 ± 0.1% in the greenhouse). Two productive perennials, Sarcocornia pacifica (pickleweed) and Frankenia salina (alkali heath), outgrew Triglochin; yet these biomass dominants produced 44%–45% less shoot biomass in greenhouse pots with Triglochin than without. However, we did not find this reduction in the field where roots were unconfined. In the greenhouse, δ15N values were higher for species grown with 15N-enriched Triglochin, indicating that this species made N available to its neighbors. The δ15N values for plants grown in the field exceeded background levels, also indicating that the marsh plain assemblage took up N released by Triglochin. We conclude that Triglochin can influence the restoration of salt marsh vegetation by accumulating N and releasing its tissue N to neighbors as leaves and roots decompose, while simultaneously reducing the biomass of neighbors. The seasonally deciduous Triglochin is low in shoot biomass, yet competitively superior in N uptake. Because this often-ignored species has limited tidal dispersal, we suggest restoration plantings, including tests of its ability to facilitate diversity where S. pacifica, the marsh plain dominant, might otherwise form monocultures.https://www.frontiersin.org/articles/10.3389/fevo.2022.851055/fullCalifornianitrogen sharingroots15N tracertidal salt marshTriglochin concinna |
| spellingShingle | Hem Nalini Morzaria-Luna Hem Nalini Morzaria-Luna Joy B. Zedler Salt marsh restoration surprise: A subordinate species accumulates and shares nitrogen while outcompeting salt marsh dominants Frontiers in Ecology and Evolution California nitrogen sharing roots 15N tracer tidal salt marsh Triglochin concinna |
| title | Salt marsh restoration surprise: A subordinate species accumulates and shares nitrogen while outcompeting salt marsh dominants |
| title_full | Salt marsh restoration surprise: A subordinate species accumulates and shares nitrogen while outcompeting salt marsh dominants |
| title_fullStr | Salt marsh restoration surprise: A subordinate species accumulates and shares nitrogen while outcompeting salt marsh dominants |
| title_full_unstemmed | Salt marsh restoration surprise: A subordinate species accumulates and shares nitrogen while outcompeting salt marsh dominants |
| title_short | Salt marsh restoration surprise: A subordinate species accumulates and shares nitrogen while outcompeting salt marsh dominants |
| title_sort | salt marsh restoration surprise a subordinate species accumulates and shares nitrogen while outcompeting salt marsh dominants |
| topic | California nitrogen sharing roots 15N tracer tidal salt marsh Triglochin concinna |
| url | https://www.frontiersin.org/articles/10.3389/fevo.2022.851055/full |
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